In the industrial manufacture of products that are assembled from components according to individual specifications, the generation of the specific engineering data for each of the individually specified products is an essential process step. The information processing involved in this process step has been hitherto performed almost exclusively by humans, as a result of which this process step is time-consuming, expensive and error-prone.
A theoretical possibility of converting graphs (graph grammars), in which a predetermined set of transformation rules is applied once or repeatedly to a root node of the graph and a complex graph is generated therefrom, has been known from the literature (e.g., Ehrig et al.: Graph Grammars and Their Application to Computer Sciences, Springer Lecture Notes CS 291, 1986). In an analogous extrapolation of this process to the area of engineering diagrams, the original master diagram could be converted into a target engineering diagram by the application of a set of rules, which act in the same way for all similar symbols and for identical symbol constellations. A conversion in which two identical symbols or symbol constellations are treated individually differently depending on external data during the transfer into the target engineering diagram is thus not possible.
Furthermore, programs and processes for putting together macrosymbols into engineering diagrams by means of rules on the basis of specification data have been known from the literature (e.g., M. Heinrich: Expert System for the Preparation of Circuit Diagrams, Automatisierungstechnische Praxis atp, Vol. 31 (1989), No. 4, pp. 190-195). However, the processes have the serious drawback that the macrosymbols must be drafted in advance and the formal and factual correctness of the engineering diagrams possibly generated during the fitting together of the macrosymbols must be ensured in advance, because the information in the macrosymbol and their connection network structure and their external connectability are not known to the rule evaluation engine and cannot be deducted. This makes decisively more difficult and increases signficantly the cost for creating and maintaining the knwoledge base and for generating the target engineering diagram.
Furthermore, various processes for determining values for variables by means of rules on the basis of data have been known from the literature (e.g., C. L. Forgy: Rete: A fast algorithm for the many pattern/many object pattern match problem, Artificial Intelligence, Vol. 19 (1982), No. 1, pp. 17-37) and from patents (e.g., DE P 30 43 563.3-53). One theoretically possible process for generating engineering data now consists of determining the components of the product on the basis of the specification by evaluating a set of rules and of subsequently determining the symbols of the components and/or their operational units from this parts list and of generating the engineering data by spatial arrangement processes known from the literature (e.g., M. May: xc3x9cber das Layout netzartiger Systeme [Layout of Network-like Systems], Postdoctoral Thesis, Akad. d. Wiss. der DDR,. Berlin, 1990). The process requires the setting up of general rules for designing graphs on the basis of the components. Such processes rarely attain an attractive appearance, because the effect of the placement rules is difficult to predict, and the human expert who specifies the basic knowledge has no possibility of expressing his graphic design wishes.
The primary object of the present invention is to accomplish the task of automatically generating by computer such engineering diagrams, which control the manufacturing process of the individualized product, on the basis of specification data and on the basis of the basic knowledge about the individual products that can be theoretically manufactured within a product class, in a process that can be carried out by computer, and to show how the basic knowledge is expediently represented in the memory of the information processing unit carrying out the process. The human expert formulating the basic knowledge shall now be able to determine the graphic design of the engineering data, and the problems of knowledge representation and knowledge management, which occur in the prior-art processes, shall be avoided.
This object is accomplished according to the present invention
by an original master diagram being stored in a coded form in a memory of the information processing unit, which is used as the generic representation of the variation spectrum of the product, wherein at least one symbol Si in the original master diagram corresponds to every possible component Ki,
by a coding of the condition Bi, which specifies the presence of the component or of the indicated operational units of the component Ki in an instantization/instance of the product that satisfies the specification, being stored in a memory of the information processing unit for each symbol Sir which corresponds to the component or to the indicated operational units of the component Ki,
by the memories being provided such that values or the attributes of the specification of the product, which attributes are included in the condition, are able to be determined from the coding of a condition Bi directly or indirectly, and
by a target engineering diagram Zx being generated as specific manufacturing data for the product Px to be manufactured according to the specification X from the original master diagram by performing a check for all symbols Sj of the original master diagram, for which a condition is contained in the memory, by the computerized evaluation of the associated condition Bj, using the values of the attributes of the specification, to determine whether the condition Bj is met, and the symbol Sj is taken over into the target engineering diagram Zx only if the condition Bj is met.
The various features of novelty which characterize the invention are pointed out in particular in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying descriptive matter in which a preferred embodiment of the invention is discussed.